This invention relates generally to the field of blood flow, and in particular to the optimization of blood flow to the heart and brain in states of low blood pressure, elevated intracranial pressure, and cardiac arrest. In one aspect, the invention relates to the intentional manipulation of intrathoracic pressures to facilitate such blood flow. In another aspect, the invention relates to techniques for continuously supplying oxygen to the patient while techniques are employed to enhance the amount of negative intrathoracic pressure.
Inadequate blood flow can have serious consequences and may result from a variety of conditions. For example, those suffering from low blood pressure may have inadequate blood flow to the heart and brain. This is especially true when low blood pressure is the result of blood loss, such as from a serious wound, or in the setting of cardiac arrest.
Decreased cerebral perfusion secondary to increased intracranial pressure or cerebral artery occlusion is generally regarded as a leading cause of morbidity and mortality in the United States for children and young adults. Brain swelling and increased intracranial pressure from trauma and other illnesses often results in a decrease in blood flow to the brain with long-term neurological consequences. Because the skull cannot expand, the increased pressures within the brain can lead to death or serious brain injury. While a number of therapies have been evaluated in order to reduce brain swelling, including use of hyperventilation and steroids, an effective way to treat intracranial pressures remains an important medical challenge. As described in copending U.S. Pat. No. 7,082,945, the effects of high intracranial pressures may be addressed by decreasing intracranial pressure and increasing cerebral spinal fluid flow and, to a lesser extent, increasing blood flow to the brain. The complete disclosure of this application is herein incorporated by reference.
Similarly, those suffering from cardiac arrest lose essentially all blood flow. If not promptly restored, the loss of blood flow can lead to brain injury or death, among other ailments. A variety of techniques have been employed to treat patient's suffering from cardiac arrest. Such techniques typically require providing periodic ventilation. Such techniques can be challenging, especially when focusing on repeatedly compressing the chest.